Various valve designs used in the past have incorporated sleeves indexed by j-slot devices to selectively align and misalign ports. In one example the ball that lands on a seat to allow application of pressure cycles to operate the j-slot is blown through the seat after a change in valve position. This is illustrated in U.S. Pat. No. 7,416,029. Another device is in essence a sliding sleeve that allows flow uphole and the sleeve, which is mounted to a j-slot, can be cycled from uphole as flow from uphole acts to close a flapper on top of the sleeve for pressure cycling. This is shown in US Publication 2008/0196898.
Other designs use a j-slot to unlock a lock in conjunction with a plug that can then disappear as illustrated in U.S. Pat. Nos. 5,765,641; 6,119,783 and 6,026,903. Other designs use relatively movable mandrel components where cycles of picking up and setting down weight actuate a j-slot to operate a flapper, as shown in U.S. Pat. No. 4,458,762. Some designs use a j-slot to unlock a lock so that a flapper can then operate. A plug is landed on a seat which then is dissolved. Some examples of combinations of some of these features are U.S. Pat. Nos. 7,270,191; 6,904,975 and US Publication 2009/0242199.
Other designs provide a flowpath constriction to create differential pressure on a flow tube to open a flapper. These designs such as the MC Injection Valves from Halliburton and the A Series Injection Valve from Schlumberger restrict access through the valve for advancing other tools. The Model J Wireline Retrievable Injection Valve from Baker Hughes opens on a predetermined flow through a restriction. Some hydraulically operated safety valves had a feature to lock a flapper open after the flapper was displaced with a flow tube driven by a hydraulic piston. In this design shown in U.S. Pat. No. 6,902,006 the flame holding the flapper was itself shifted when the flapper was open to catch the edge of the flapper in a top groove of a sleeve below. Yet a few other applications that use flow bore restrictions to create a force to move a tube to open a flapper are U.S. Ser. Nos. 12/433,134, filed on Apr. 30, 2009 entitled Innovative Flow Tube, 12/469,310, filed on May 20, 2009, entitled Flow-Actuated Actuator, and 12/469,272, filed on May 20, 2009, entitled Flow-Actuated Actuator and Method.
The present invention deals with flapper type valves with a preferred use in injection service. The design provides a way of operating the flapper without control lines. In deep applications there will be high hydrostatic pressure in the control line that would have to be offset with a very large return spring. While a dual control line system can offset this hydrostatic effect in deep applications there is additional expense and operational issues from doubling up the control lines and running them with a string into the subterranean location. In the preferred embodiment there is no need for control lines. A flapper is operated by a sleeve that responds to pressure cycles against a seated ball or plug to push the flapper open after a predetermined number of cycles. The ball, plug or other object is removed from its blocking position on a seat preferably by dissolving it so that flow can commence. The preferred application is injection service where water, salt water, chemicals, CO2 or steam can be the flowing fluid. When it is desired to close the flapper another object can be landed in the same seat and the cycling with pressure repeated to allow a return spring to raise the flow tube so that a torsion spring on the flapper pivot can move the flapper to the closed position against its seat. As few as a single application and removal of pressure cycle can be used to change the flapper position between open and closed.
In an alternative embodiment an actuation sleeve pushes the flapper open as well as engaging or contacting a counter sleeve below that is engaged to a j-slot. On release of pressure a return spring on the counter sleeve raises it to retain the flapper in the open position while a separate return spring biases the actuation sleeve up. A second ball or other object landed in the seat of the actuation sleeve once again displaces the actuation sleeve against the counter sleeve. This time the counter sleeve is held against its return spring by the j-slot so that on release of pressure the torsion spring on the flapper allows the flapper to pivot closed when the actuation sleeve is also pushed up by its return spring. After a use of either the first or the second object, either is removed preferably by dissolving to get either object out of the flow path.
The dissolving of the object can occur by fluids such as water, saltwater in the wellbore, acid added to the wellbore, or by other reactive or dissolving agents present or added to the wellbore. Other ways to fail the object to get it out of the flow path are also contemplated.
Those skilled in the art will better appreciate the scope of the invention from a review of the description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention is determined by the appended claims.